It uses 50 different metrics to gauge closeness and 50 to gauge
importance of contacts for voice and the same again for email and
chat. The key is to monitor deviations from the average way in
which a trader communicates with all counterparties and changes
to the way a trader communicates with particular counterparts.

So all interactions will be monitored, and anything outside the
norm will be suspicious, it seems. Here's more about the
thinking:

"We’re looking for changes in behaviour and anomalies in how
people communicate," Adylov tells Euromoney. "So for example, an
important thing to notice may be how often a trader laughs on the
phone. Our system establishes a true picture of the relationship
between a trader and his or her counterparts. So, if a trader
laughs more often in conversation with a person, uses more slang
in emails to them or swears more, that is a good indication of
how close they are. As well as being a designated counterparty,
that person – maybe working at another firm – is clearly the
trader’s mate. The trader may also be good mates with his risk
manager. Does that represent a conflict of interest to bear in
mind?"

The moral here is don't laugh to hard on your next client call.
Your compliance department might get suspicious.